I report on the introduction, spread and current distribution of the Greek Fir (Abies cephalonica) (Pinaceae) in Austria. The species was introduced in Austria in the second half of the 19th century as an ornamental tree. Very locally, it has already been planted in forests for the first time likely in the late 19th century, while some more trial forestry plantations have only been established in the 1970s. Currently, 14 escaped occurrences of A. cephalonica are known, occurring in parks, gardens and forests. All escaped populations are found on the eastern rim of the Northern Calcareous Alps south of Vienna. Some of these escaped populations are large (up to at least 1000 young trees) and spreading. Inferring from the size of escaped plants and from the literature, spread at some sites must already have started in the mid-1970s at latest. Based on the data presented here, I conclude that A. cephalonica should be considered as locally established in Austria.

The herb Arctotheca calendula (capeweed) is reported as a new record for Iran. A detailed description, a distribution map, colour photographs of an herbarium sample, and diagnostic features are provided to facilitate identification. The species was first observed in 2017 in the Miankaleh Biosphere Reserve, one of the thirteen UNESCO Biosphere Reserves in Iran. Since 2017, the A. calendula population has been thriving and locally expanding. As capeweed is generally described as an invasive species with negative impacts, having both high reproductive potential and highly mobile propagules, we suggest prioritizing an eradication intervention for this alien weed before it becomes too widespread.

Invasion by alien trees and shrubs has been well documented in many regions of the world, and horticulture and forestry are the main pathways of their introduction. A lack of proper management and control of cultivated alien trees and shrubs can lead to their establishment and invasion in new areas. The early detection of alien woody species outside cultivation is crucial for their control and protection of native habitats. Prunus virginiana is a North American shrub or small tree cultivated and established in a few countries in Europe. It is considered invasive in the state of Alaska in the United States, as well as in Sweden and Central European Russia. It forms dense thickets that can outcompete native vegetation, impair visibility and limit access to recreational areas. In this paper, we present a new record of P. virginiana in north-eastern Poland, with a new range extension of about 300 km in the east from known spontaneous localities in Central Europe. The status of the species in Polish flora is discussed.

Phytolacca americana is a large perennial invasive alien plant indigenous to the eastern United States. In Europe, it usually infests forest edges, open woodlands and other disturbed habitats. In this study, the occurrence of the species as a weed in crop fields in Austria was analysed based on distribution data collected from different sources. Moreover, P. americana was surveyed in a selected area in southern Austria (Styria) and its behaviour as weed was analysed by phytosociological relevés. The situation of the species in Austrian neighboring countries (the Czech Republic, Germany, Hungary, Italy, Slovakia, Slovenia, Switzerland) was also briefly investigated. The results show that P. americana is generally rare on arable land in Austria and its neighboring countries. The survey and distribution data collected, however, showed that P. americana occurred locally more abundant in crop fields. Two factors may have contributed to this phenomenon: (i) high propagule pressure from large forest and ruderal populations, (ii) and small-scale and less intensive cultivation practices (e.g. weed control) of particularly low growing crops such as oil pumpkin. The study illustrates the need to further monitor the occurrence of P. americana in crop fields and its potential impact.

We report here the first occurrences of two alien cacti species from Algeria. During field surveys from 2016 to 2022 in the Skikda region (north-eastern Algeria), ten populations of Opuntia monacantha (Willd.) Haw. were recorded. This species is reported here as naturalized alien species for the first time for Algeria and the second time for mainland North Africa. The same surveys also yielded three localities of Opuntia tomentosa Salm-Dyck, reported here as casual species for the first time for Algeria and mainland North Africa. Both species colonize various habitats (coastal dune, maquis, cliffs, roofs, gutters, tree trunks) and they propagate by stem fragments. However, O. tomentosa also reproduces from seeds, and birds seem to play a role in the dispersal of this species. We discuss the potential of both species for further spread in Algeria, and argue that increased botanical surveys may lead to the recording of further alien cacti species.

The occurrence of the alien earwig Forficula smyrnensis Audinet-Serville, 1838, which is native in the eastern Mediterranean basin, is reported for the first time in the Czech Republic. The established population was found in the urban deciduous forest in Prague in 2021. During the last decade, the adventive occurrence of this species was also reported from Austria and Italy, and due to its hidden way of life and nocturnal activity, the species may survive unnoticed elsewhere in Central and Western Europe. The spread of F. smyrnensis probably results from accidental, passive introductions by humans. Gastrointestinal tract analysis revealed the prevalence of animal food (cuticle fragments of several unidentified insect species) in the studied specimens of F. smyrnensis. Given its feeding habit and preferred habitats, this species should not cause economic damage and should not directly compete with native Dermaptera species.

The present contribution reports the current distribution of the Asian scolytine beetle Anisandrus maiche Kurentzov (Curculionidae: Scolytinae, Xyleborini) in Italy. Previously, in the entire European Union, this species was known only from a single specimen collected in the Treviso province of Northeast Italy in 2021. The data presented here considerably increase the distributional range of A. maiche in Italy, and clearly show that this ambrosia beetle species is established and widespread in at least two northern Italian regions, namely Lombardy and Veneto.

Primavelans glabricollaris is a cheilostomatid bryozoan described in 2021 from Korean coastal waters. Here, we report the first observations of this Pacific species from samples at two different locations during soft-bottom surveys of the North Sea in 2019. Its European discovery predates the actual species description from the year 2021. The Pacificincolidae are not native to Europe, and since Primavelans glabricollaris was found only recently, despite earlier surveys at the same locations, we regard it as a non-indigenous species. Its disjunct distribution within the North Sea as well as its rare occurrence in soft-bottom habitats far off the coasts of the Netherlands and Germany might indicate some specific anthropogenic introduction mechanism different from the usual ballast water or shellfish import vectors known for these coasts.

The Mediterranean Sea is one of the most heavily impacted areas by biological invasions worldwide, with over 650 non-indigenous species (NIS) reported as established in 2019. Information about the distribution of NIS in the basin is often fragmented or non-existent due to factors such as lack of finance, expertise, and appropriate surveillance systems. Citizen science might represent a reliable tool in monitoring the spread of NIS, being able to overcome the challenges of scientific monitoring. In the context of the citizen science project “Is it alien to you? Share it!!!”, we hereby first report the presence of the Australian spotted jellyfish Phyllorhiza punctata von Lendenfeld, 1884 in the marine waters of Cyprus and review its known distribution in the Mediterranean Sea. Although this taxon does not represent a direct threat to human health or tourism as it bears no painful sting, it already caused important ecological and economic damages in other regions of the world, and thus its further spread in Cypriot waters requires appropriate monitoring.

The occurrence of the alien invasive freshwater snail Sinotaia cf. quadrata is reported for the first time in Africa. This species is a global invader of freshwater bodies as evidenced by its very recently reported discoveries in Europe and the Americas. We use DNA barcoding and phylogenetic analysis to confirm species identity and show low genetic divergence with haplotypes from Japan. The introduction of S. cf. quadrata to South Africa is undoubtedly recent, but its introduction pathways are currently uncertain. Unintentional introduction via the aquarium or aquaculture trades are a possibility, but this snail may have been introduced for human consumption. The S. cf. quadrata population is established in the artificial impoundment known as Zoo Lake in Johannesburg. Population dynamics indicate very high fecundity and densities of 1078 ind. m^-2 ± 236 SE can be attained in disturbed and polluted environments. It has the potential to spread over the northern parts of South Africa, into the Kruger National Park and into Mozambique. Further monitoring is recommended in the region.

This paper presents the first record of the Asian date mussel Arcuatula senhousia (Benson, 1842) from the southern coast of the Algerian Basin in the Western Mediterranean Sea. The species was first observed in June 2019 in El Mellah Lagoon, a coastal lagoon located in the El Kala UNESCO biosphere reserve (north-eastern Algeria). Additional individuals were also collected monthly, between July and December. Arcuatula senhousia was found in shallow subtidal habitats dominated by the seagrass Zostera noltei (Hornemann, 1832) at a maximum density of 1,321 ± 1,167 ind.m^-2. The maximum observed shell length was 32 mm, indicating that A. senhousia may have existed for more than a year in adjacent area in El Mellah Lagoon and moved probably into our survey area in 2019 as either adults (via fouled vessels) or, less likely, planktonic larvae (via currents). Live specimens were observed attached to Z. noltei leaves and rhizomes and, to a lesser degree, on empty shells of the cockle Cerastoderma glaucum (Bruguière, 1789). The introduction of the invasive Asian date mussel into this lagoon may lead to changes in the structure and functioning of this unique shallow coastal ecosystem and requires further study.

The Asian mussel Arcuatula senhousia is known as a successful invader into coastal and estuarine environments worldwide. We here report its Northward expansion along the French Atlantic coast evidenced by new records from the commercial ports of La Rochelle (Bay of Biscay) and Dunkirk (North Sea), both in 2018, following sampling of benthic macroinvertebrates. To date, the Asian mussel has only been observed along the French coast from the Mediterranean Sea and the Southern part of the Bay of Biscay. Its presence in these new locations, which are important for international maritime transport, is most likely related to ship ballast water and/or sediment as vector of introduction. These new insights suggest that this species has not yet finished its expansion process, which could be at the origin of irreversible impacts on ecosystem structure, functioning and services.

Global shipping is a common vector of non-native species (NNS), especially biofouling organisms. Ports with heavy ship traffic can contain a higher proportion of NNS compared to surrounding coastal habitats. Port Canaveral, Florida, is a busy and growing port, but little is known about the native and non-native species present. A baseline survey was designed to identify barnacle species, conspicuous members of the biofouling communities growing on structures in the port, and determine their origin status (i.e., native or NNS). In addition to species identity, the relative abundance of each species and NNS at five different sites during two time periods was assessed. Eight species of barnacles were identified, three of which are non-native in Florida. Barnacle communities differed by site and time period, with a significant interaction between the two factors. During both time periods, NNS comprised more than 90% of the barnacles at four of the sites. While this survey provides a baseline for barnacles present at Port Canaveral, Florida, expanding the surveys to include other organisms will give a more complete view of the number of NNS present at the port, supporting managers’ future assessment of community changes.

During intertidal rocky shore surveys on the east coast of South Africa in 2018, the non-indigenous giant purple barnacle Megabalanus tintinnabulum (Linnaeus, 1758), a well-known fouling and globally-invasive species, was discovered. This motivated a survey of the entire South African east coast at 31 rocky shore sites, which confirmed that breeding populations of this barnacle have been established in most wave-exposed low-shore intertidal habitats between the Mozambique border and Mkambati Nature Reserve and that its current South African distribution spans 725 km of coastline. Another non-indigenous and common fouling species, the titan acorn barnacle M. coccopoma (Darwin, 1854), was discovered at three of the sites, its local distribution spanning 370 km of coastline. While currently uncommon, this species is known to reach high densities in other non-native regions. Both Megabalanus species are large and conspicuous and were not found during extensive surveys in the 1990s and early 2000s, suggesting that their introduction and spread occurred within the past two decades. Their establishment on subtidal reefs remains to be confirmed but is likely, based on frequent encounters of empty shells washed up on beaches or on buoys. Prior to this, no non-indigenous invasive species have been reported to occur on intertidal rocky shores of the subtropical South African east coast, while the country’s south and west coasts have experienced severe ecological impacts from invasive mussels and barnacles since the 1970s. Two alternative processes have likely led to the introduction and spread of the two species: (i) their dispersal from ship fouling communities and spread along the coast from focal points, such as local ports and harbours; or (ii) their arrival by southward range expansions of tropical populations concurrent with recent climate-mediated thermal shifts in the region. The supporting evidence of both are discussed, as well as management implications.

The presence of the non-indigenous calanoid copepod Pseudodiaptomus marinus is reported for the first time in the North Aegean Sea, in Thessaloniki Bay, a semi-enclosed basin in the inner part of Thermaikos Gulf. Both female and male specimens were collected during monitoring sampling in the study area. The pathway of arrival of the species most probably is via ballast water, since the sampling site is next to the port of Thessaloniki, which experiences high traffic of commercial maritime transport. Continuous monitoring of the area is needed to reveal the establishment status of the species and its impacts on the zooplankton community.

The Japanese aorid amphipod Grandidierella japonica (Stephensen, 1938) and the North American opossum shrimp Neomysis americana (S.I. Smith, 1873) are reported here for the first time in Belgium. Both G. japonica and N. americana were found in hyperbenthic samples taken from just above the sediment surface during long-term monitoring of the Schelde estuary. Grandidierella japonica was detected for the first time in 2018 and has since appeared regularly in low numbers. Neomysis americana has probably been overlooked for some time and was found in high numbers (n = 155/40 m³) for the first time in July 2012. Since N. americana has been found with regular occurrence and in fairly high numbers (n = 0–3530/40 m³), a well-established population is assumed. The arrival of N. americana probably went unnoticed for some time due to confusion with the native species Neomysis integer.

The invasive non-native Ponto-Caspian amphipod Chelicorophium robustum has been recorded for the first time in Great Britain. In October 2021 a single specimen was found at a site on the River Thames near Hampton, London during a programme of surveys undertaken on behalf of Thames Water Utilities Ltd. The programme employed a novel method of multi-habitat survey devised to target the collection and identification of aquatic non-native species from a range of water body types. Surveys were conducted in accordance with a strict biosecurity protocol. Non-native taxa found alongside C. robustum included other Ponto-Caspian crustaceans, bivalve molluscs and a polychaete worm plus additional invasive macroinvertebrates from Asia, North America and New Zealand.

The translocation of nonnative crayfish across the United States is of great concern given the ecological consequences of the taxon. Nonnative crayfish have been reported to reduce densities of native crayfish, alter benthic invertebrate communities, decrease macrophyte biomass, reduce reproductive success of fish, and diminish the genetic integrity of native crayfish through hybridization. As part of ongoing research into the development of a state-wide crayfish monitoring program, rusty crayfish Faxonius rusticus (Girard, 1852) were observed in McPherson State Fishing Lake, Kansas (decimal degrees = 38.4819, -97.4682). Sampling occurred at McPherson State Fishing Lake and Battle Creek between June 22 and July 1 2021. A total of three rusty crayfish were collected and consisted of two females and one male. Individual carapace lengths varied from 27 to 35 mm. No rusty crayfish were collected in Battle Creek upstream of the lake. Although the mode of introduction is unknown, anthropogenic releases of live crayfish have been implicated in other rusty crayfish introductions. Therefore, greater restrictions on the use of live crayfish in Kansas may be an important consideration for management agencies. Furthermore, additional research is needed to determine the exact mode of introduction to curtail future spread of the species in the state. Our results highlight the need to consistently monitor crayfish populations to document the occurrence and distribution of a potentially deleterious species.

In this study, 110 male and female blue crabs Callinectes sapidus Rathbun, 1896 were collected from the coastal waters of Morocco, Africa using baited traps between February and December 2021. Here, we report the first occurrence of the species in the ports of Tangier and Tangier Med (the Strait of Gibraltar). These additional records support recent work by others of hundreds of blue crabs (mostly females) collected from different locations along the Moroccan coastline. Combined, these records represent the distribution of the species throughout northwestern Africa. These new locations may be indicative of natural expansion from a previously introduced population in the Tangier Med, which is the largest port in Africa. Additional population genetics are needed to further elucidate questions surrounding the continued spread of C. sapidus along the northwestern African coast.

Here, we report the recent capture (October, November 2021) of the following three non-indigenous species (NIS) from the Indo-Pacific in the Mediterranean Sea: the fishes Naso annulatus and Scatophagus argus and the brachyuran Charybdis (Charybdis) natator. The record of the white margin unicorn fish N. annulatus from the island of Malta represents the first for this species from the basin. Both the spotted scat S. argus and the ridged swimming crab C. natator were found in Egyptian waters, in localities significantly far from ones previously reported. Possible vectors of introduction for these three NIS to the Mediterranean locations in question include Lessepsian migration, ship-mediated transport, aquarium release, and are briefly discussed.

Six specimens of Bregmaceros nectabanus were collected during the acoustic survey MEDIAS in two consecutive years, off Termoli (Italy) in 2020 and in Albanian waters in 2021, during two night shallow hauls. We report the northernmost record of the alien species in the Mediterranean Sea (Northern Adriatic Sea, FAO fishing area 37.2.1) and one of the highest number of individuals caught in a single haul. This finding testifies a recent geographical spread to the eastern Mediterranean Sea from its distribution area in the Indo-Pacific Ocean and Red Sea, reaching the Adriatic Sea during the 2019. Our records support the hypothesis of a possible establishment of B. nectabanus in this basin.

Several alien species of freshwater turtles have been imported to the Republic of Korea from various countries, and then released to the wild by breeders and as a part of religious practices throughout Korea. Here, we evaluated the number of subspecies of the alien freshwater turtle Trachemys scripta in the wild on Jeju Island, Korea. We confirmed the presence of three alien subspecies of freshwater turtles with higher number and broader distribution compared to previous studies in 2007 and 2015. There were 134 adult and 48 juvenile Trachemys scripta elegans in 41 locations; nine adult Trachemys scripta scripta in seven locations; and two adult Trachemys scripta troostii in two locations. Illegal release by humans and potential reproduction in the wild probably contributed to the increase in their numbers. Early detection of invasive alien species is crucial for preventing their spread. Therefore, to minimize their negative impacts on the natural ecosystem of Jeju Island, we suggest the continuous monitoring of invasive freshwater turtles (including the evaluation of their survival, growth, and reproduction) and the strengthening of regulations to prevent continued releases to the wild.

Coyotes are successful generalist carnivores that are favored by anthropogenic activities. We document a range expansion for the species into the State of Quintana Roo, Mexico. We used camera traps to determine the presence and documented two separate events during 2020 and 2021. We discuss the implications for the presence of the species in highly developed areas dedicated to tourism and livestock. Habitat transformation seems to be a conducive factor that facilitates colonization and will have future impacts on urban developments in the region.